1. Field of the Invention
The invention relates to an apparatus of the type comprising a feed table for receiving a blank, a device for picking up and transporting the blank to a circular shaping device, and a welding system for cutting the blank to desired dimensions and welding the edges to form a sleeve-shaped printing plate.
2. Description of the Related Art
An apparatus of this type, which merely requires the plate-shaped blank to be inserted manually and, after the plate has been inserted, automatically permits the circular shaping operation and the exact register-maintaining positioning of the plate ends to be joined or to be welded, is described in U.S. Pat. No. 5,557,960.
In order to avoid cutting the plate-shaped blank to length outside this apparatus by means of a sheet-metal shear, while maintaining the dimensions, U.S. Pat. No. 5,499,580 discloses improving the production operation of the sleeve-shaped printing form in this apparatus to the effect that the plate-shaped blank, having a width corresponding to the form cylinder, is cut to a length that is greater than the circumference of the form cylinder. The blank in the in-register, rounded state is cut to length, maintaining its dimensions, in the welding apparatus by means of the laser beam as a cutting device, so that at least one piece of waste is produced. The piece of waste is removed, and the two plate edges forming the start and end of the printing form are set opposite each other with no overlap and are welded to each other.
U.S. Pat. No. 5,992,727 discloses a further generic apparatus. Here, above the feed table and in the housing which can be closed so as to be secure against radiation, an opening is left through which a device for fixing the plate-shaped blank as a planar blank, in the form of a fixing frame that can be adjusted to the appropriate plate size, can be moved out of the housing over the feed table in order to pick up the blank.
The fixing frame comprises two fixing bars which can be adjusted on a carriage in accordance with the distance between the plate edges of the blank to be joined and can be set longitudinally on the respective plate edge. The fixing frame further comprises a register device, which is designed such that it interacts with a register system on the plate-shaped blank. For example, the start and end of the blank can be fixed in-register to the fixing bars in each case by means of a pin register and a register hole system belonging to the plate-shaped blank.